Using image analysis and ray tracing, my goal is to develop a quantitative, predictive model to explain the variance in leaf and hoot morphology for the temperate zone species, Sassafras albidum as it occurs across the eastern United States. A model of this type has not been achieved in Plant sciences; and if successfully developed, could have heuristic appeal into the causes behind plant performance (i.e., growth, survival & corp yield). Considering that leaves house the photosynthetic machinery that produces the trophic energy for all terrestrial biota; and considering that crops provide the foundation of the human economy, it is interesting that the meaning of variability in leaf form eludes explanation even though some theoretical and experimental studies indicate that the sizes and shapes of leaves and their arrangement on the shoot, influence photosynthesis, water relations, growth, and food yield. Individual leaves will be reconstructed from their Fourier coefficients. These leaf images will come from trees where we have an understanding of leaf and shoot morphology, photosynthesis, and light regime. We will simulate in the Sun computer the three-dimensional display of leaves involving number of leaves on the shoot, surface areas and shapes of each, shoot phyllotaxy, internode length, angle of leaf attachment, posture of blade, angle of stem, and leaf optical properties. In software we will vary these factors to understand how they influence the absorption of sunlight. Ray tracing will allow us to determine if there are particular configurations for the foliage that are local optima or functionally equivalent in terms of maximization of light absorption, minimization of self-shading, evenness of light absorption and heat and gas exchange performance. These analytical simulations based upon our knowledge of the functional biology of the plant, will allow us to measure and conduct "experiments" for combinations of leaf and shoot morphologies that are impossible to do otherwise. This has never been done and it could improve our understanding of the fundamental relationships between leaf form, shoot form, and shoot autonomy in carbon fixation and use.